Air-heating apparatus



May .28, 1929. W 1,714,695

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Patented May 28, 192 9. A

UNITED STATES PIATENVNT OFFICE.

WILLIAM A. Row, or DETROI MIcIIIGAN-,- AssIe oR, BY MEsNE ASSIGNMENTS, To

AMERIcAN BLOWER CORPORATION, or DETROIT, MIcIIIeAN, A coRroRATIoN or DELAWARE.

AIR-HEATING APPARATUS.

Application filed August -22,.1e25. Serial No. 51,888.

. This invention relates to improvements in air heating apparatus and more particularly to unit heaters of the general type comprising heat radiating elements enclosed within a casing and a fan associated with the casing for circulating air adjacent the heating elements.

The object of the invention is to provide an improved, simple, light, portable, compact, unit heater adapted to be easily assembled, handled and installed, and that will be highly eflic-ient.

A particularly important novel characteristic of the invention resides in the special construction of plate provided at one end of the casing constituting in a single unitary 7 structure a combined support for the fan produced at low of'Fig. 3;

and motor unit," a casing portion for enclosing the heating elements, and an outer ring member for the fan, the particular form of adapter plate afiording a light and at the same time still, strong, compact, efiicient support for the fan and motor unit, and further providing for the natural flow of air from the fan and the equalization or uniform distribution of the air delivered by the fan throughout the heating elements, the special adapter plate being directly instrumental in providing a simple, compact, light, portable heater unit of high efiiciency in heat transmission that can be easily assembled, handled, and installed and can be cost.

- The invention, with other objects and advantages thereof, and the particular construction, combination and arrangement of parts comprising the same-will be understood from the hereinafter contained detailed description, when considered in connection with the accompanying drawings, forming a part hereof, and illustrating one embodiment of the invention In the drawings Figure 1 is a rear elevation of an air heater unit constructed in accordance with the present invention;

Fig. 2 is a ,vertical section with parts shown in side elevation;

Fig. 3 is a horizontal section on an enlarged scale;

Fig. 4 is a detailed section onthe line 44 Fig. 5 is a side elevation, with parts broken away, of the unit heater mounted upon a reclrculating box or caslng; and

Fig. 6 is a front elevation of the heater pnit and recirculating box illustrated in While a specific embodiment of the invention is illustrated in the drawings, it

will, of course, be understood that minor changes and variations in the particular construction shown, may be made, and the invention embodied in other forms, as will appeal to those skilled in the art, and falling within the scope of the appended claims, without departing from the spirit of the lnvention.

Referring to a detail descri tion of the particular embodimentv of the Invention illustrated in the drawings, 1 designates a rectangularshaped open-ended sheet metal cas-' ing having top, bottom, and side walls 1 1"1. Within the casingl are a serie's of'heat radiating elements in the form oftubes or pipes 2 adapted to receive a heating fluid, preferably steam. The steam tubes or pipes 2, which are shown arranged in rows extending transversely of the casing 1 are connected at their ends with vertical headers 3 secured to the side walls 1-of the casing.-

The headers 3; which are semi-cylindrical shape in cross section, have a flat front wall 3 and a curved rear wall 3 provided with interlocking seams or folds 4 at either side, and the flat front wall 3 is provided with angled extensions 5 through which'the headers are secured to the sides 1 of the casing v 1 by rivets 6. In the construction shown the tubes 2 are of straight, seamless copper and provided with helical radiator fins 2" of brass. The front walls I") of the headers are formed by thin, flexible copper plates and are provided with, flanged openings 7 slightly smaller than the exterior diametero'f the, tubes 2, the ends of which are presse into I the flanged openings 7 of the thin flexible front plates 3 and soldered thereto, steam tight joints being thus provided and the flexibility of the front plates 3 of the headers permitting ofexpansion and contraction of the parts. One of the headers 3 is provided near its upper part with an inlet 8 for connection with any suitable source of steam or other suitable heating fluid supply, and the other header 3 has an air outlet 9 at its lower part for connection with any suitable form of drain system, preferably a vacuum system, not shown, for carrying off the water or condensation. The headers 3 at the inlet 8 and the outlet 9 are equipped with threaded nipples 10 for connection with a feed pipe 11 and an exhaust pipe 12. said coupling nipples 10 extending through the side walls 1 of the casing 1 and being secured thereto by key plates 13 engaging grooves 14 in the coupling nipples 10 and se cured to the side walls 1 of the casing 1 by rivets 15.

Located directly in rear of the rows of tubular elements 2 and disposed centrally of the bank of heater tubes and the casing 1 is a motor driven fan for forcing a circulation of air over the surfaces of the heater tubes. The fan and motor unit shown is of well known construction comprising a motor 16 and fan 17, the latter being of the propeller or disc type. The fan and motor unit is carried by a plate 18 secured to and extending over the rear end of the casing 1. The plate 18 which is rectangular shape in outline has a central opening 19 and an outer marginal portion 20 adapted to fit against flanges 21 on the casing 1. The plate 18 is dished outwardly, as shown, for its greater part, from the flat attaching marginal portion 20, to a point 22, from which it is reversedly dished to provide an inwardly extending annular curved part 23 adjacent its central opening 19. The plate 18 is de-tachably secured to the casing 1 by bolts and nuts 24, 25, the bolts 24 passing through apertures in the plates 21 of the casing 1 and the attaching marginal portion 20 of the plate 18. The plate 18 is also formed with flat seat portions 26 for engagement by attaching portions 27 at the inner ends of radial arms 28 on the casing of the motor 16, the fan and motor unit being detachably secured to the plate 18 with the fan 17 disposed centrally of the opening 19 of the plate 18 by bolts and nuts 29, 30.

The plate 18 is a light, pressed sheet metal construction. The inner annular curved part 23 of the plate 18 forms an outer ring member of stream line design for the fan 17, and the outwardly dishing of the major por tion of the plate 18 is such as to provide for the natural flow of air from the fan 17 and the equalization or uniform distribution of the air throughout the heater tubes 2, said inwardly curved part 23 and the outwardly dishing of the plate 18 also functioning as stifi ening means and in this respect being important factors in the provision of a light sheet metal plate construction that is capable of forming an efiicient support for the fan and motor unit, said plate serving as a casing portion for enclosing. the heater tubes, a support for the fan and motor unit, and an outer ring member-for the fan.

Any suitable means may be employed for supporting the heater unit, which as will be understood owing to its light compact nature susceptible of a wide range of use and may be arranged in many different ways. In Figs. 5 and 6 of the drawings, the unit is shown associated with a recirculating box or casing 31. The recirculating box 31, which is shown rectangular shape and constructed of sheet metal, has an inlet opening 32 at its lower end and an outlet 33 at its upper part, the heater unit being suitably secured to the front of the recirculating box as shown. The heater unit may be provided with a guard grating extending over the frontthereof and secured to flanges 36 on the casing 1.

It will be noted that by the special construction and arrangement of parts, hereinbefore set forth, a simple, light, compact, inexpensive construction of unit heater is afforded. The special construction of adapter plate is such as to insure an advantageous distribution of the air throughout the tubular heater elements and high efficiency in heat transmission and the construction is one that can be easily assembled, moved from place to place, and easily installed.

WVhat I claim is 1. An air heating device of the character described including an open-ended sheet metal casing, a series of heat radiating elements within the casing, a sheet pressed metal plate member secured to and extend ing over one end of the casing, and a fan and motor unit mounted on the end plate, said end plate constituting means for supporting the fan and motor unit from the casing, the end plate having a central opening at which the fan is disposed to force air therethrough into the casing, said end plate being dished outwardly and having an annular inwardly curved part adjoining its central opening constituting the outer ring for the fan, said inwardly curved part and the outward dishing of the end plate serving as stiffening means for the end plate.

2. An air heating device of the class described including an open-ended sheet metal casing, heat radiating elements within the casing, a pressed sheet metal plate member secured to and extending over one end of the casing, and a rotary propeller type fan and motor unit mounted on the end plate, said end plate constituting means for supporting the fan and motor unit from the casing, the end plate having a central opening at which the fan isdisposed to force air therethrough into the casing, said plate being dished outwardly and provided with an annular inwardly curved part adjoining thereof, a series of heat its central opening constituting the outer ring for the fan; and said plate having flattened seat portions adjacent its central opening, the fan and motor unit having radial attaching arms provided with outer portions to fit against the said flattened seat portions of the end plate.

3. An air heating scribed, including an open-ended sheet metal casing having angularly disposed flange portions at one end, heat radiating elements within the casing, a pressed sheet metal plate member secured to and extending over one end of the casing, and a rotary disk type fan and motor unit mounted on the end plate, said end plate constituting means for supporting the fan and motor unit from the casing, the end plate having a central opening at which the fan is disposed, said plate having an annular curved part adjoining its central opening constituting an outer ring member for the fan and stiffening means for said plate, and said plate having a flat peripheral attaching flange to fit against the flange portions of the casing. v

4. An air heating device of the class described including an open-ended sheet metal casing having flange portions at one end radiating elements within the casing, a pressed sheet metal plate member secured to and extending over one end of the casing, and a fan and motor unit device of the class de-.

mounted on the end plate, said end plate constituting means for supporting the fan and motor unit from the casing, the end plate having a central opening at which the fan is disposed to force airtherethrough into the casing, said end plate having a flat peripheral attaching flange to fit against the marginal flange portions of the casing, and said plate being dished outwardly from a point ad Oining its flat peripheral attaching flange.

5. An air. heating device of the class described, including an open-ended sheet metal rectangular shaped casing provided with marginal flange portions at one end, a series of heat radiating elements within the casing,

a rectangular shaped sheet metal plate memthe marginal flange portions of the casing, v

and said end plate being dished outwardly from a' oint adjoining its peripheral attaching ange.

In testimony whereof I hereunto aflix my signature.

' WILLIAM A. ROWE. 

